Semiconductor manufacturing apparatus and method of manufacturing semiconductor device

ABSTRACT

In one embodiment, a method of manufacturing a semiconductor device includes forming a first film on a substrate. The method further includes etching the first film with first gas including carbon and fluorine to form a concave portion in the first film and form a second film in the concave portion. The method further includes treating the second film by using the second film to second gas or second liquid, wherein the second film is treated without plasma.

CROSS REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2020-150725, filed on Sep. 8,2020, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate to a semiconductor manufacturingapparatus and a method of manufacturing a semiconductor device.

BACKGROUND

When a concave portion is formed in a process target film on asubstrate, a sidewall film is occasionally formed on a side face of theconcave portion to prevent the concave portion from taking a bowingshape. However, the side face of the concave portion cannot besufficiently protected with the sidewall film depending on a method offorming the sidewall film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 2C are sectional views showing a method of manufacturing asemiconductor device of a first embodiment;

FIG. 3 is a sectional view showing a structure of the semiconductordevice of the first embodiment;

FIGS. 4A and 4B are plan views showing examples of a structure of asemiconductor manufacturing apparatus of a second embodiment;

FIGS. 5A and 5B are sectional views showing the structure of thesemiconductor manufacturing apparatus of the second embodiment, and astructure of a semiconductor manufacturing apparatus of a comparativeexample of the second embodiment;

FIG. 6 is a sectional view showing a structure of semiconductormanufacturing apparatus of a first modification of the secondembodiment; and

FIGS. 7A and 7B are sectional views showing structures of semiconductormanufacturing apparatuses of second and third modifications of thesecond embodiment.

DETAILED DESCRIPTION

Embodiments will now be explained with reference to the accompanyingdrawings. In FIGS. 1A to 7B, the same components are given the samesigns and their duplicated description is omitted.

In one embodiment, a method of manufacturing a semiconductor deviceincludes forming a first film on a substrate. The method furtherincludes etching the first film with first gas including carbon andfluorine to form a concave portion in the first film and form a secondfilm in the concave portion. The method further includes treating thesecond film by using the second film to second gas or second liquid,wherein the second film is treated without plasma.

First Embodiment

FIGS. 1A to 2C are sectional views showing a method of manufacturing asemiconductor device of a first embodiment. The semiconductor device ofthe present embodiment is, for example, a three-dimensional memory.

First, a lower layer 2 is formed on a substrate 1, and a stacked filmalternately including a plurality of insulating layers 3 and a pluralityof insulating layers 4 is formed on the lower layer 2 (FIG. 1A). Theinsulating layers 3 are examples of first insulating layers, and theinsulating layers 4 are examples of second insulating layers. Next, anupper layer 5 is formed on the stacked film, and a hard mask layer 6 isformed on the upper layer 5 (FIG. 1A). The lower layer 2, the insulatinglayers 3, the insulating layers 4, the upper layer 5 and the hard masklayer 6 are a process target film on the substrate 1 of the presentembodiment. The process target film is an example of a first film.

The substrate 1 is, for example, a semiconductor substrate such as asilicon (Si) substrate. FIG. 1A shows an X-direction and a Y-directionwhich are parallel to a surface of the substrate 1 and perpendicular toeach other, and a Z-direction perpendicular to the surface of thesubstrate 1. In the present specification, the +Z-direction is regardedas the upward direction, and the −Z-direction is regarded as thedownward direction. The −Z-direction may coincide with the direction ofgravity or does not have to coincide with the direction of gravity.

The lower layer 2 includes, for example, insulators such as a siliconoxide film(s) (SiO₂) and a silicon nitride film(s) (SiN), and aconducting layer formed between the insulators. The insulating layers 3are, for example, silicon nitride films. The insulating layers 4 are,for example, silicon oxide films. The upper layer 5 includes, forexample, insulators such as a silicon oxide film(s) and a siliconnitride film(s), and a conducting layer formed between the insulators.The hard mask layer 6 is, for example, an organic film.

Next, an etching treatment of etching the process target film on thesubstrate 1 is performed (FIG. 1A). Specifically, an opening for forminga memory hole M is formed in the hard mask layer 6 by lithography andetching. Then, the insulating layers 3, the insulating layers 4 and theupper layer 5 are etched using the hard mask layer 6 as a mask.Consequently, the memory hole M is formed halfway in the insulatinglayers 3, insulating layers 4 and the upper layer 5. The memory hole Mand the opening are examples of a concave portion. The aforementionedetching treatment is an example of a first treatment.

The aforementioned etching treatment is performed using gas G1including, for example, the carbon element and the fluorine element. Thegas G1 includes, for example, C_(x)H_(y)F_(z) gas. Note that C, H and Fdenote carbon, hydrogen and fluorine, respectively, and x, y and zdenote an integer of one or more, an integer of zero or more, and aninteger of one or more, respectively (x≥1, y≥0, z≥1). When y=0,C_(x)H_(y)F_(z) is fluorocarbon, and when y≠0, C_(x)H_(y)F_(z) ishydrofluorocarbon. Examples of the C_(x)H_(y)F_(z) gas include C₄F₆ gas,C₄F₈ gas and CH₂F₂ gas. The gas G1 is an example of first gas fortreating the first film.

In the aforementioned etching treatment, the etching is performed withC_(x)H_(y)F_(z) plasma generated from the C_(x)H_(y)F_(z) gas, and asidewall film 11 is formed on the surfaces and the like of theinsulating layers 3, the insulating layers 4, the upper layer 5 and thehard mask layer 6 which are exposed in the memory hole M and the opening(FIG. 1A). The sidewall film 11 is, for example, a fluorocarbon filmincluding the carbon element and the fluorine element. The sidewall film11 is an example of a second film.

Next, a reforming treatment of reforming the sidewall film 11 isperformed (FIG. 1B). In the present embodiment, the sidewall film 11 isreformed, for example, by reducing the sidewall film 11. FIG. 1B shows areformed sidewall film 12 obtained by reforming the sidewall film 11.The aforementioned reforming treatment is an example of a secondtreatment.

The aforementioned reforming treatment is performed using, for example,gas G2 including the hydrogen element. The gas G2 includes, for example,HCOOH (formic acid) gas. Note that O denotes oxygen. Formic acid isliquid at ambient temperature and ambient pressure. In the presentembodiment, the HCOOH gas is generated from HCOOH liquid, and thesidewall film 11 is reformed using the HCOOH gas. In the aforementionedreforming treatment, the sidewall film 11 is reformed by exposing thesidewall film 11 to the HCOOH gas. In the present embodiment, while theaforementioned etching treatment is performed using plasma, theaforementioned reforming treatment is performed not using plasma. Thegas G2 is an example of second gas for treating the second film.

Hereafter, the reforming treatment of the sidewall film 11 is describedin detail.

As mentioned above, the sidewall film 11 is, for example, a fluorocarbonfilm including the carbon element and the fluorine element. While thesidewall film 11 functions as a protecting film for the process targetfilm in etching, there is a case where the sidewall film 11 converselycontributes etching when ions at high energy enter the sidewall film 11.Namely, there is a concern that the sidewall film 11 promotes etching ofthe process target film in the memory hole M. This is because thesidewall film 11 serves as a source of CF_(a) in the followingexpression (1).

SiO₂+CF_(a)→SiF_(b)↑+CO_(c)↑  (1)

Note that a, b and c denote composition ratios. As mentioned above, theinsulating layers 4 are, for example, silicon oxide films (SiO₂ films).Moreover, there is a case where the lower layer 2 and the upper layer 5include silicon oxide films. These silicon oxide films are possiblyetched through the reaction of expression (1).

According to expression (1), when the quantity of fluorine atoms in thesidewall film 11 is reduced, the supply amount of CF_(a) can be reducedand the process target film in the memory hole M can be restrained frombeing etched. Therefore, the sidewall film 11 is reformed in theaforementioned reforming treatment, and specifically, fluorine atoms inthe sidewall film 11 are caused to react with hydrogen atoms in the gasG2 (reduction reaction) to be eliminated as hydrogen fluoride. Thereby,the reformed sidewall film 12 richer in carbon than the sidewall film 11can be obtained, and a fluorine concentration in the reformed sidewallfilm 12 can be reduced to be less than a fluorine concentration in thesidewall film 11. In other words, a ratio of carbon amount per fluorineamount in the reformed sidewall film 12 becomes larger than a ratio ofcarbon amount per fluorine amount in the sidewall film 11 by beingtreated with the gas G2. Therefore, even when ions at high energy enterthe reformed sidewall film 12, the reaction of expression (1) hardlyoccurs and the process target film in the memory hole M is restrainedfrom being etched.

The present embodiment therefore makes it possible to restrain thesidewall film 11 from contributing etching and to cause the reformedsidewall film 12 to function as a protecting film. This makes itpossible to restrain the memory hole M from taking a bowing shape.

Subsequently, annealing in the reforming treatment of the sidewall film11 is described in detail.

It can be considered that the aforementioned reforming treatment isperformed using plasma generated from the gas G2 as in theaforementioned etching treatment. The plasma can promote the reformingtreatment. However, the plasma is possibly not able to reach a deepplace in the memory hole M. There is a possibility, in such a case, thatthe sidewall film 11 is not sufficiently reformed at the deep place inthe memory hole M and the process target film in the memory hole M isnot sufficiently restrained from being etched. This problem isconsidered as more apparent, for example, when three-dimensionalmemories are to have a further larger capacity and to make the aspectratio of memory holes M further higher.

Therefore, in the aforementioned reforming treatment of the presentembodiment, the sidewall film 11 is reformed by exposing the sidewallfilm 11 to the gas G2. This makes it possible to reform the sidewallfilm 11 not using plasma. This reforming treatment makes it possible tosufficiently reform the sidewall film 11 down to the deep place in thememory hole M and makes it possible to form a more conformal reformedsidewall film 12 than in the case using plasma. Exposing the sidewallfilm 11 to the gas G2 includes, for example, annealing the sidewall film11 in an atmosphere of the gas G2 or exposing the sidewall film 11 tothe gas G2 at a predetermined temperature.

Examples of gas included in the gas G2 include H₂ (hydrogen) gas and theaforementioned HCOOH (formic acid) gas. When the reforming treatment isperformed using H₂ gas, annealing is desirably performed in anatmosphere of H₂ gas in order to sufficiently reduce a fluorocarbon film(sidewall film 11) and the annealing is desirably performed at or above300° C. In general, an upper limit of a process temperature in a dryetching chamber is 100 to 150° C. and it is difficult to reduce thefluorocarbon film (sidewall film 11) with H₂ gas at or below the upperlimit. Therefore, when the aforementioned etching treatment is performedin this chamber, it is difficult to perform the reforming treatmentusing H₂ gas subsequently in the chamber. Therefore, when the reformingtreatment is performed using H₂ gas, this reforming treatment and theaforementioned etching treatment are desirably performed in separatechambers.

Meanwhile, HCOOH gas has higher reducing ability than H₂ gas and has100° C. of low boiling point. Therefore, when the reforming treatment isperformed using HCOOH gas, annealing is performed at 100 to 150° C. inan atmosphere of HCOOH gas. Performing the annealing at 100 to 150° C.makes it possible to sufficiently reduce the fluorocarbon film (sidewallfilm 11). Therefore, when the reforming treatment is performed usingHCOOH gas, this reforming treatment and the aforementioned etchingtreatment can be performed in the same chamber. Namely, the reformingtreatment and the aforementioned etching treatment can be performedin-situ.

The reforming treatment may be performed by feeding HCOOH gas into anetching chamber at a predetermined temperature. For example, HCOOH gasmay be fed after the temperature of the etching chamber is set to atemperature not more than the upper limit of the process temperature inthe etching chamber. For example, HCOOH gas may be fed into the etchingchamber at 150° C. The temperature of an etching chamber in an etchingtreatment is typically room temperature to 60° C. When the reformingtreatment of the sidewall film sufficiently progresses, HCOOH gas may befed into the etching chamber at a temperature comparable to that of theetching treatment. The temperature of the etching chamber is, forexample, a stage temperature in the etching chamber. Using HCOOH gasmakes it possible to simplify steps of manufacturing a semiconductordevice of the present embodiment and to improve productivity ofsemiconductor devices.

Formic acid (HCOOH) is a substance that is liquid at ambient temperatureand ambient pressure. Therefore, in the reforming treatment of thepresent embodiment, HCOOH gas is generated from HCOOH liquid, and thesidewall film 11 is reformed using the HCOOH gas. HCOOH gas has 100° C.of low boiling point and can be vaporized by a vaporizer to beintroduced into the chamber. The gas G2 may include gas other than HCOOHgas and may include other gas, for example, obtained from a substancethat is liquid at ambient temperature and ambient pressure. Moreover, inthe aforementioned reforming treatment, the sidewall film 11 may bereformed by annealing the sidewall film 11 in an atmosphere of liquidinstead of the gas G2. This liquid is an example of second liquid. Theliquid is, for example, HCOOH liquid. Moreover, in the aforementionedreforming treatment, the sidewall film 11 may be reformed by exposingthe sidewall film 11 to the liquid instead of the gas G2 at apredetermined temperature.

Gas included in the gas G2 may be organic gas such as HCOOH gas or maybe inorganic gas. Examples of the organic gas include HCHO(formaldehyde) gas and CH₃OH (methyl alcohol) gas. Examples of theinorganic gas include gas of a substance having a silyl group (Si—R₃),and include SiH₄ gas, Si₂H₆ gas and SiH₂[NH(C₄H₉)]₂ gas. Note that Siand N denote silicon and nitrogen, respectively. Other examples of theinorganic gas include AsH₃ (hydrogen arsenide) gas, B₂H₆ (borane) gas,H₂Se (hydrogen selenide) gas, PH₃ (phosphine) gas and GeH₄ (germane).Moreover, organic liquid or inorganic liquid may be used for theaforementioned reforming treatment instead of the gas G2. When thereforming treatment is performed using SiH₄ gas, it is expected thatsubstitution reaction that F atoms are replaced by H atoms as in thefollowing expression (2) takes place.

(—CF₂—)_(n)+SiH₄→(—CH₂—)_(n)+SiF₄↑  (2)

Note that n denotes an integer of one or more.

The gas G2 may include another element along with the hydrogen elementor instead of the hydrogen element. The element is, for example, thesulfur element. The gas G2 may include, for example, H₂S (hydrogensulfide) gas, SF₆ (sulfur hexafluoride) gas or COS (carbonyl sulfide)gas along with HCOOH gas or instead of HCOOH gas. When the gas G2includes, for example, H₂S gas, the sidewall film 11 is reformed byannealing the sidewall film 11 in an atmosphere of H₂S gas. Liquidincluding the sulfur element may be used for the aforementionedreforming treatment instead of the gas G2 including the sulfur element.

Moreover, the gas G2 may include He (helium) gas, Ar (argon) gas, Kr(krypton) gas or Xe (xenon) gas along with gas including the hydrogenelement and/or the sulfur element.

After that, in the present embodiment, by alternately repeating theaforementioned etching treatment and the aforementioned reformingtreatment, the memory hole M is completed. In other words, the memoryhole M of the present embodiment is formed by alternately, repeatedlyfeeding the gas G1 and the gas G2. In the aforementioned reformingtreatment, the aforementioned annealing is performed along with feedingthe gas G2. Details of these treatments are described below.

After the step of FIG. 1B, the etching treatment of etching theinsulating layers 3 and the insulating layers 4 is performed again usingthe gas G1 (FIG. 1C). Consequently, the processing of forming the memoryhole M progresses and a bottom face of the memory hole M lowers. In thisetching treatment, etching is performed with C_(x)H_(y)F_(z) plasma, anda sidewall film 13 is coincidently formed on the surfaces of theinsulating layers 3 and the insulating layers 4 exposed in the memoryhole M. The sidewall film 13 has properties similar to those of thesidewall film 11 and is formed beneath on the reformed sidewall film 12.The sidewall film 13 is also an example of the second film.

Next, the reforming treatment of reforming the sidewall film 13 isperformed again using the gas G2 (FIG. 2A). FIG. 2A shows a reformedsidewall film 14 obtained by reforming the sidewall film 13. In thisreforming treatment, the sidewall film is reformed by annealing thesidewall film 13 in an atmosphere of HCOOH gas. The reformed sidewallfilm 14 has properties similar to those of the reformed sidewall film12.

Next, the etching treatment of etching the insulating layers 3 and theinsulating layers 4 is performed again using the gas G1 (FIG. 2B).Consequently, the processing of forming the memory hole M progresses,and the bottom face of the memory hole M further lowers. In FIG. 2B, thememory hole M penetrates the lower layer 2 to reach the substrate 1, andthe memory hole M is completed. In this etching treatment, etching isperformed with C_(x)H_(y)F_(z) plasma, and a sidewall film 15 iscoincidently formed on the surfaces of the lower layer 2, the insulatinglayers 3 and the insulating layers 4 which are exposed in the memoryhole M. The sidewall film 15 has properties similar to those of thesidewall films 11 and 13 and is formed beneath on the reformed sidewallfilm 14. When the memory hole M is not completed by the step of FIG. 2B,the aforementioned reforming treatment and the aforementioned etchingtreatment are alternately, repeatedly performed afterward until thememory hole M is completed.

Next, after the reformed sidewall films 12 and 14, the sidewall film 15and the hard mask layer 6 are removed, a memory insulator 7 and achannel semiconductor layer 8 are sequentially formed in the memory holeM (FIG. 2C). As mentioned later, the memory insulator 7 is formed bysequentially forming a block insulator, a charge storage capacitor and atunnel insulator in the memory hole M. In the step of FIG. 2C, thememory insulator 7, the channel semiconductor layer 8 and a coreinsulator may be sequentially formed in the memory hole M.

After that, various inter layer dielectrics, plug layers and line layersand the like are formed on the substrate 1. By doing so, thesemiconductor device of the present embodiment is manufactured.

The method shown in FIGS. 1A to 2C can also be applied to a processtarget film other than the lower layer 2, the insulating layers 3, theinsulating layers 4, the upper layer 5 and the hard mask layer 6 and aconcave portion other than the memory hole M. This method can also be,for example, applied to a case of forming a contact hole and a trench ininter layer dielectrics and a case of forming a memory hole in a stackedfilm alternately including a plurality of electrode layers (for example,polysilicon layers) and a plurality of insulating layers (for example,silicon oxide films).

The plurality of insulating layers 3 of the present embodiment arereplaced by a plurality of electrode layers in a replacing stepperformed after the steps shown in FIGS. 1A to 2C. In the replacingstep, a plurality of hollows are formed between the insulating layers 4by removing the insulating layers 3, and the plurality of electrodelayers are buried in the hollows. Examples of such electrode layers aredescribed with FIG. 3.

FIG. 3 is a sectional view showing a structure of a semiconductor deviceof the first embodiment. FIG. 3 shows an example of a semiconductordevice manufactured by the method of the present embodiment.

FIG. 3 shows a memory cell portion and a stepwise contact portion of athree-dimensional memory. In FIG. 3, the lower layer 2 includes aninsulator 2 a, a source-side conducting layer 2 b and an insulator 2 c,and the upper layer 5 includes a cover insulator 5 a, a drain-sideconducting layer 5 b, an inter layer dielectric 5 c and an inter layerdielectric 5 d. Moreover, the aforementioned plurality of insulatinglayers 3 have been replaced by a plurality of electrode layers 3′including tungsten (W) layers.

FIG. 3 further shows block insulators 7 a, charge storage capacitors 7 band tunnel insulators 7 c included in memory insulators 7. The memoryinsulator 7 and the channel semiconductor layer 8 are formed, forexample, by sequentially forming the block insulator 7 a, the chargestorage capacitor 7 b and the tunnel insulator 7 c on the surface of thememory hole M, removing the block insulator 7 a, the charge storagecapacitor 7 b and the tunnel insulator 7 c from a bottom of the memoryhole M, and after that, burying the channel semiconductor layer into thememory hole M. In this stage, the channel semiconductor layer 8 and acore insulator may be sequentially buried into the memory hole M. Thechannel semiconductor layers 8 are electrically connected to a diffusionlayer L in the substrate 1.

FIG. 3 further shows a plurality of contact holes H formed in the upperlayer 5, and a plurality of contact plugs 9 formed in these contactholes H. The contact plugs 9 are formed so as to be electricallyconnected to the corresponding electrode layers 3′.

As above, the memory holes M of the present embodiment are formed byperforming the etching treatment using the gas G1 and the reformingtreatment using the gas G2. In the etching treatment, etching of thememory holes M progresses and the sidewall films (sidewall films 11 andthe like) are formed in the memory holes M. In the reforming treatment,the sidewall films are reformed by exposing the sidewall films to thegas G2.

The present embodiment therefore makes it possible to restrain, withsidewall films, the memory holes M from taking bowing shapes and makesit possible to appropriately realize the memory holes M that have a highaspect ratio. The present embodiment furthermore makes it possible tosufficiently reform the sidewall films down to the deep places in thememory holes M with heat and makes it possible to preferably protect thememory holes M with the reformed sidewall films (reformed sidewall films12 and the like). As above, the present embodiment makes it possible topreferably form the memory holes M in the process target film on thesubstrate 1 by reforming the sidewall films not using plasma.

Moreover, the sidewall films of the present embodiment are reformed, forexample, using HCOOH gas as the gas G2. This makes it possible to reduce(reform) the sidewall films with the gas G2 having high reducingability. Consequently, this also makes it possible to reduce thetemperature of annealing and to perform the aforementioned etchingtreatment and the aforementioned reforming treatment in the samechamber. As above, the present embodiment makes it possible topreferably form the memory holes M in the process target film on thesubstrate 1 by reforming the sidewall films using HCOOH gas. Althoughthe sidewall films are reformed with HCOOH gas and the heat in thepresent embodiment, the sidewall films may be reformed using HCOOH gaswithout annealing when the heat is unnecessary. The sidewall films maybe reformed using gas other than HCOOH gas.

Second Embodiment

FIGS. 4A and 4B are plan views showing examples of a structure of asemiconductor manufacturing apparatus of a second embodiment.

FIG. 4A shows a first example of the structure of the semiconductormanufacturing apparatus of the present embodiment. The semiconductormanufacturing apparatus of the first example includes a plurality ofFOUP (Front-Opening Unified Pod) stages 21, a load lock chamber 22, atransfer chamber 23, a plurality of treatment chambers 24 and acontroller 25.

The FOUP stages 21 are used for placing FOUPs (not shown) for containingthe substrates 1. When the substrate 1 is conveyed into thesemiconductor manufacturing apparatus, a FOUP is placed on any of theFOUP stages 21 and the substrate 1 in the FOUP is conveyed into the loadlock chamber 22. When the substrate 1 is conveyed out of thesemiconductor manufacturing apparatus, the substrate 1 in the load lockchamber 22 is conveyed out into a FOUP on any of the FOUP stages 21. Thesubstrate 1 conveyed into the semiconductor manufacturing apparatus ofthe first example is conveyed into any of the treatment chambers 24 viathe load lock chamber 22 and the transfer chamber 23.

Each treatment chamber 24 has a function of performing theaforementioned etching treatment and a function of performing theaforementioned reforming treatment (reducing treatment). In the firstexample, the substrate 1 is conveyed into any of the treatment chambers24, and the aforementioned etching treatment and the aforementionedreforming treatment alternately, repeatedly performed on the substrate 1in this treatment chamber 24. In the etching treatment, etching of thememory hole M in the process target film is caused to progress and thesidewall film (sidewall film 11 or the like) is formed in the memoryhole M, by treating the process target film on the substrate 1 using thegas G1. In the reforming treatment, the sidewall film is reformed intothe reformed sidewall film (reformed sidewall film 12 or the like) bytreating the sidewall film using the gas G2. In this reformingtreatment, the sidewall film may be reformed by exposing the sidewallfilm to the gas G2 in the treatment chamber 24 at a predeterminedtemperature instead of reforming the sidewall film by annealing thesidewall film in an atmosphere of the gas G2.

The semiconductor manufacturing apparatus of the first example is used,for example, for a case using HCOOH gas as the gas G2. The treatmentchambers 24 can be used for dry etching and upper limits of processtemperatures in chambers of the treatment chambers 24 are typically 100to 150° C. Annealing cannot be performed at higher temperature than 150°C. in the treatment chambers 24. Nevertheless, using HCOOH gas as thegas G2 makes it possible to reform the sidewall film sufficiently byannealing at 100 to 150° C. The first example makes it possible toperform the aforementioned etching treatment and the aforementionedreforming treatment in-situ in the same treatment chamber 24.

The controller 25 controls various kinds of operation of thesemiconductor manufacturing apparatus. For example, the controller 25controls the conveyance of the substrate 1, and the etching treatmentsand the reforming treatments in the treatment chambers 24. Thecontroller 25 is, for example, a processor, an electric circuit, acomputer or the like.

FIG. 4B shows a second example of the structure of the semiconductormanufacturing apparatus of the present embodiment. The semiconductormanufacturing apparatus of the second example includes an etchingchamber 26 and a reduction chamber 27 instead of the aforementionedplurality of treatment chambers 24.

The etching chamber 26 has a function of performing the aforementionedetching treatment. The reduction chamber 27 has a function of performingthe aforementioned reforming treatment (reducing treatment). In thesecond example, the substrate 1 is alternately, repeatedly conveyed intothe etching chamber 26 and into the reduction chamber 27, theaforementioned etching treatment is performed on the substrate 1 in theetching chamber 26, and the aforementioned reforming treatment isperformed on the substrate 1 in the reduction chamber 27. In the etchingtreatment, etching of the memory hole M in the process target film iscaused to progress and the sidewall film (sidewall film 11 or the like)is formed in the memory hole M, by treating the process target film onthe substrate 1 using the gas G1. In the reforming treatment, thesidewall film is reformed into the reformed sidewall film (reformedsidewall film 12 or the like) by treating the sidewall film using thegas G2. In this reforming treatment, the sidewall film may be reformedby exposing the sidewall film to the gas G2 in the reduction chamber 27at a predetermined temperature instead of reforming the sidewall film byannealing the sidewall film in an atmosphere of the gas G2.

The semiconductor manufacturing apparatus of the second example is used,for example, for a case using H₂ gas as the gas G2. The etching chamber26 can be used for dry etching and an upper limit of a processtemperature in a chamber of the etching chamber 26 is typically 100 to150° C. Annealing cannot be performed at higher temperature than 150° C.in the etching chamber 26. Meanwhile, when H₂ gas is used as the gas G2,the sidewall film is desirably reformed by annealing at or above 300° C.Therefore, the reforming treatment in the second example is performed inthe reduction chamber 27 separately provided from the etching chamber26. The reduction chamber 27 may perform the reforming treatment usingliquid such as HCOOH liquid instead of the gas G2. The reduction chamber27 in this case may be a liquid chemical treatment chamber such as a wettreatment chamber.

As in the case of the first example, the controller 25 controls variouskinds of operation of the semiconductor manufacturing apparatus. Forexample, the controller 25 controls the conveyance of the substrate 1,the etching treatment in the etching chamber 26, and the reformingtreatment in the reduction chamber 27.

FIGS. 5A and 5B are sectional views showing a structure of thesemiconductor manufacturing apparatus of the second embodiment, and astructure of a semiconductor manufacturing apparatus of a comparativeexample of the second embodiment.

FIG. 5A shows the structure of the semiconductor manufacturing apparatusof the present embodiment, and specifically shows the structure of thetreatment chamber 24 in FIG. 4A. In FIG. 5A, the treatment chamber 24includes a dry etching chamber 31, a stage 32, a gas feeder 33 an MFC(Mass Flow Controller) 34, a shower head 35, an annealer 36, pipes 41and 42, and heaters 43, 44 and 45. The dry etching chamber is an exampleof a container, the gas feeder 33 is an example of a first feeder, andthe MFC 34 is an example of a first device. The pipe 41 is an example ofa second channel, and the pipe 42 is an example of a first channel. Theheater 43 is an example of a second heater, the heater 44 is an exampleof a first heater, and the heater 45 is an example of a third heater.

The dry etching chamber 31 can contain the substrate 1 which is a targetfor dry etching. In the present embodiment, the aforementioned etchingtreatment and the aforementioned reforming treatment on the substrate 1are performed in the dry etching chamber 31.

The stage 32 is used for supporting the substrate 1 in the dry etchingchamber 31.

The gas feeder 33 feeds gas with which a film on the substrate 1 can betreated to the dry etching chamber 31. For example, the gas feeder 33feeds the gas G1 for etching the process target film and forming thesidewall films (sidewall film 11 and the like), and the gas G2 forreforming the sidewall films into the reformed sidewall films (reformedsidewall film 12 and the like). The gas G1, G2 is fed to the dry etchingchamber 31 sequentially via the pipe 41, the MFC 34 and the pipe 42, andfed to the shower head 35 in the dry etching chamber 31.

The MFC 34 has a function of measuring a mass flow rate of gas and afunction of controlling the mass flow rate of the gas. The MFC 34 of thepresent embodiment is arranged between the pipe 41 and the pipe 42 andcan measure and control the flow rate of gas fed to the dry etchingchamber 31 from the gas feeder 33. For example, the controller 25mentioned above (FIG. 4A) can receive the flow rate of gas measured bythe MFC 34 and control the flow rate of the gas via the MFC 34.

The shower head 35 ejects gas fed from the gas feeder 33 into the dryetching chamber 31. The shower head 35 of the present embodiment isarranged near the ceiling of the dry etching chamber 31 and ejects thegas downward in the dry etching chamber 31. Thereby, a film on thesubstrate 1 placed on the stage 32 can be treated using the gas.

The annealer 36 anneals the substrate 1 on the stage 32. Thereby, thesidewall film on the substrate 1 can be annealed during theaforementioned reforming treatment. The annealer 36 in the presentembodiment is provided in the stage 32.

The heater 43 is provided around the pipe 41 and heats gas passingthrough the pipe 41. Therefore, the heater 43 can heat the gas towardthe MFC 34 from the gas feeder 33. The heater 43 of the presentembodiment has, for example, a cylindrical shape surrounding the pipe41.

The heater 44 is provided around the pipe 42 and heats gas passingthrough the pipe 42. Therefore, the heater 44 can heat the gas towardthe dry etching chamber 31 from the MFC 34. The heater 44 of the presentembodiment has, for example, a cylindrical shape surrounding the pipe42.

The heater 45 is used for heating the shower head 35 and a space betweenthe ceiling and the shower head 35 in the dry etching chamber 31.Therefore, the heater 45 can heat gas in the shower head 35 and gastoward the shower head 35 in the dry etching chamber 31.

In the treatment chamber 24 of FIG. 5A, C_(x)H_(y)F_(z) gas is used asthe gas G1 and HCOOH gas is used as the gas G2, for example. Inaddition, in the reforming treatment, the sidewall film on the substrate1 is annealed at 100 to 150° C. of annealing temperature. In this case,there is a concern that when the temperature of the HCOOH gas is lowerthan the annealing temperature, the temperature of the sidewall filmdrops during the annealing, which results in insufficient reforming ofthe sidewall film.

In the present embodiment, in order to restrain such an event fromoccurring, the gas G2 is heated by the heaters 43, 44 and 45 while thegas G2 is being fed from the gas feeder 33 for the aforementionedreforming treatment. This makes it possible to restrain the temperatureof the gas G2 from significantly dropping until the gas G2 reaches thesidewall film from the gas feeder 33.

In order to effectively restrain the temperature of the gas G2 fromdropping as above, the gas G2 is desirably heated as close to thesidewall film as possible. Heating the gas G2 with the heater 44 and/orthe heater 45 makes it possible to more effectively restrain thetemperature of the gas G2 dropping than in the case of heating the gasG2 with the heater 43.

The heater 43 can be used, for example, for preventing HCOOH gas frombeing cooled back into HCOOH liquid. Moreover, the heaters 44 and 45 canbe used, for example, for preventing HCOOH gas from being cooled backinto HCOOH liquid and for feeding the HCOOH gas at high temperature tothe sidewall film.

The heater 44 of the present embodiment extends to the inlet of the dryetching chamber 31 from the outlet of the MFC 34. Namely, one end of theheater 44 extends to the outlet of the MFC 34, and the other end of theheater 44 extends to the inlet of the dry etching chamber 31. This makesit possible to restrain the gas G2 from being cooled between the one endof the heater 44 and the outlet of the MFC 34 and the gas G2 from beingcooled between the other end of the heater 44 and the inlet of the dryetching chamber 31. Likewise, the heater 43 of the present embodimentextends to the inlet of the MFC 34.

Operation of the treatment chamber 24 in FIG. 5A is controlled by thecontroller 25 mentioned above (FIG. 4A). For example, the controller 25controls turning on and off the annealer 36, an annealing time, anannealing temperature, turning on and off the heaters 43, 44 and 45, aheating time, a heating temperature, operations of the chamber 31, thestage 32, the gas feeder 33, the MFC 34 and the shower head 35, and thelike.

FIG. 5B shows the structure of the semiconductor manufacturing apparatusof the comparative example of the present embodiment, and specificallyshows the structure of the treatment chamber 24 similarly to FIG. 5A.Note that the treatment chamber 24 of the present comparative exampledoes not include the heater 44 or 45. Therefore, in the presentcomparative example, there is a concern that the temperature of the gasG2 significantly drops until the gas G2 reaches the sidewall film fromthe gas feeder 33. It should be noted that the heater 43 of the presentcomparative example does not extend to the inlet of the MFC 34. There isalso a concern that this disturbs restraining the temperature of the gasG2 from dropping.

FIG. 6 is a sectional view showing a structure of a semiconductormanufacturing apparatus of a first modification of the secondembodiment.

FIG. 6 shows a structure of the treatment chamber 24 of the presentmodification. The structure of the treatment chamber 24 of the presentmodification is similar to the structure of the treatment chamber 24shown in FIG. 5A except in the followings. In the present modification,the gas feeder 33, the MFC 34, the pipe 41, the pipe 42 and the heater43 are replaced by two sets of gas feeders 33 a and 33 b, MFCs 34 a and34 b, pipes 41 a and 41 b, pipes 42 a and 42 b, and heaters 43 a and 43b.

The structures and the functions of the gas feeder 33 a, the MFC 34 a,the pipe 41 a, the pipe 42 a and the heater 43 a are similar to those ofthe gas feeder 33, the MFC 34, the pipe 41, the pipe 42 and the heater43. Moreover, the structures and the functions of the gas feeder 33 b,the MFC 34 b, the pipe 41 b, the pipe 42 b and the heater 43 b aresimilar to those of the gas feeder 33, the MFC 34, the pipe 41, the pipe42 and the heater 43. Note that in the present modification, the gasfeeder 33 a feeds the gas G1 and the gas feeder 33 b feeds the gas G2.The dry etching chamber 31 is an example of the container, the gasfeeder 33 b is an example of the first feeder, the MFC 34 b is anexample of the first device, the gas feeder 33 a is an example of asecond feeder, and the MFC 34 a is an example of a second device. Thepipe 41 b is an example of the second channel, the pipe 42 b is anexample of the first channel, and the pipe 41 a is an example of a thirdchannel. The heater 43 b is an example of the second heater, the heater44 is an example of the first heater, the heater 45 is an example of thethird heater, and the heater 43 a is an example of a fourth heater.

The treatment chamber 24 of the present modification includes the heater44 only around the pipe 42 b out of the pipes 42 a and 42 b. Heating thegas G2 with the heaters 43 b, 44 and the like makes it possible torestrain the temperature of the gas G2 from significantly dropping untilthe gas G2 reaches the sidewall film from the gas feeder 33 b. Thisfurther makes it possible to restrain the temperature of the gas G2 fromsignificantly changing from the upstream to the downstream of the MFC 34b and to preferably control the flow rate of the gas G2.

FIGS. 7A and 7B are sectional views showing structures of semiconductormanufacturing apparatuses of second and third modifications of thesecond embodiment.

FIG. 7A shows a structure of the treatment chamber 24 of the secondmodification. The structure of the treatment chamber 24 of the presentmodification is similar to the structure of the treatment chamber 24 ofthe first modification except in the followings. In the presentmodification, the gas feeder 33 a, the MFC 34 a, the pipe 41 a, and theheater 43 a in the first modification are replaced by N sets of gasfeeders 33 a, MFCs 34 a, pipes 41 a, and heaters 43 a (N is a integer oftwo or more).

For example, the semiconductor manufacturing apparatus of the presentmodification is used when N types of gases are supplied from the N gasfeeders 33 a as the gas G1. The pipe 42 a in the present modificationincludes N branches that are connected to the N MFCs 34 a.

FIG. 7B shows a structure of the treatment chamber 24 of the thirdmodification. The structure of the treatment chamber 24 of the presentmodification is similar to the structure of the treatment chamber 24 ofthe second modification except in the followings. The pipe 42 a in thepresent modification is merged into the pipe 42 b. This makes itpossible to shorten the total length of the pipes 42 a and 42 b.

As above, the semiconductor manufacturing apparatus of the presentembodiment includes the treatment chambers 24 which can perform both theaforementioned etching treatment and the aforementioned reformingtreatment, and the heaters 43 (43 b), 44 and 45 for restraining thetemperature of the gas G2 from dropping. The present embodimenttherefore makes it possible to perform the method of manufacturing asemiconductor device of the first embodiment in a preferable mode withthis semiconductor manufacturing apparatus.

In the treatment chamber 24 of FIG. 5A, the sidewall film may bereformed by exposing the sidewall film to the gas G2 in the treatmentchamber 24 at a predetermined temperature instead of reforming thesidewall film by annealing the sidewall film in an atmosphere of the gasG2. In this case, the temperature of the treatment chamber 24 may beadjusted to be at the predetermined temperature with the heater 45, tobe at the predetermined temperature with the annealer 36, or to be atthe predetermined temperature with means other than these. Moreover,when the sidewall film is reformed by exposing the sidewall film to thegas G2, the annealer 36 does not have to be provided in the treatmentchamber 24 of FIG. 5A. This also applies to the treatment chambers 24 inFIGS. 6, 7A and 7B.

Moreover, the structure of the treatment chamber 24 in FIG. 5A can alsobe applied to the reduction chamber 27 mentioned above (FIG. 4B). Inthis case, the gas feeder 33 is used for feeding only the gas G2 out ofthe gas G1 and the gas G2. This also applies to the treatment chambers24 in FIGS. 6, 7A and 7B.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel apparatuses and methodsdescribed herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe apparatuses and methods described herein may be made withoutdeparting from the spirit of the inventions. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the inventions.

1. A method of manufacturing a semiconductor device, comprising: forminga first film on a substrate; etching the first film with first gasincluding carbon and fluorine to form a concave portion in the firstfilm and form a second film in the concave portion; and treating thesecond film by using the second film to second gas or second liquid,wherein the second film is treated without plasma.
 2. The method ofclaim 1, wherein the second film is treated by at least one of annealingthe second film in an atmosphere of the second gas or the second liquidand exposing the second film to the second gas or the second liquid at apredetermined temperature.
 3. The method of claim 1, wherein the firstgas includes C_(x)H_(y)F_(z) gas where C, H and F denote carbon,hydrogen and fluorine, respectively and where x, y and z denote aninteger of one or more, an integer of zero or more, and an integer ofone or more, respectively.
 4. The method of claim 1, wherein the secondgas or the second liquid includes hydrogen.
 5. The method of claim 4,wherein the second gas or the second liquid includes at least one ofhydrogen, formic acid, formaldehyde, methyl alcohol, hydrogen arsenide,borane, hydrogen selenide, phosphine, germane, and a substance having asilyl group.
 6. The method of claim 1, wherein the second gas or thesecond liquid includes sulfur.
 7. The method of claim 6, wherein thesecond gas or the second liquid includes at least one of hydrogensulfide, sulfur fluoride and carbonyl sulfide.
 8. The method of claim 1,wherein the second gas includes helium, argon, krypton or xenon.
 9. Themethod of claim 1, wherein the second gas includes gas obtained from asubstance that is liquid at ambient temperature and ambient pressure.10. The method of claim 1, wherein a ratio of carbon amount per fluorineamount in the second film increases by being treated with the second gasor the second liquid.
 11. The method of claim 1, wherein the first filmis formed by alternately stacking a plurality of first insulating layersand a plurality of second insulating layers or alternately stacking aplurality of electrode layers and a plurality of insulating layers. 12.The method of claim 1, wherein a first treatment of etching the firstfilm with the first gas and a second treatment of treating the secondfilm with the second gas or the second liquid are performed in a samechamber.
 13. The method of claim 1, wherein a first treatment of etchingthe first film with the first gas and a second treatment of treating thesecond film with the second gas or the second liquid are alternatelyperformed.
 14. A semiconductor manufacturing apparatus comprising: acontainer capable of containing a substrate; a first feeder configuredto feed, to the container, gas capable of treating a film on thesubstrate; a first device provided between the first feeder and thecontainer, and configured to control a flow rate of the gas fed from thefirst feeder to the container; and a first heater provided around afirst channel through which the gas is fed from the first device to thecontainer, and configured to heat the gas passing through the firstchannel.
 15. The apparatus of claim 14, further comprising a secondheater provided around a second channel through which the gas is fedfrom the first feeder to the first device, and configured to heat thegas passing through the second channel.
 16. The apparatus of claim 14,further comprising: a shower head configured to eject the gas into thecontainer; and a third heater configured to heat the shower head. 17.The apparatus of claim 14, further comprising an annealer configured toadjust a temperature in the container to a predetermined temperature.18. The apparatus of claim 14, further comprising: a second feederconfigured to feed, to the container, gas capable of treating the film;and a second device provided between the second feeder and thecontainer, and configured to control a flow rate of the gas fed from thesecond feeder to the container.
 19. The apparatus of claim 18, furthercomprising a fourth heater provided around a third channel through whichthe gas is fed from the second feeder to the second device, andconfigured to heat the gas passing through the third channel.